1. Field of the Invention
This invention relates to an ink-supplying device for an ink-droplet generator, particularly for an ink ejecting unit provided with a number of ink discharging orifices, namely, a multi-nozzle type of ink-jet recorder head.
2. Description of the Prior Art
Among a wide variety of recording systems hitherto known, a so-called ink-jet recording system, which is a non-impact type of recording method generating practically no noise during operation and which additionally permits high-speed recording on plain paper without any special fixing treatment, is very useful for developing various types of printers, including those for copying machines and word processors. Accordingly, various types of ink-jet recording system have been offered heretofore, some of which were further improved and commercialized and some of which are still on the way to practical use under continuous efforts.
The ink-jet recording system is a method of recording by flying droplets of recording liquid (referred to as "ink" in this specification) utilizing various operating principles to adhere to paper or other recording members. The ink-droplet generating device used for the ink-jet recording system i.e. the ink-jetting device, comprises generally ink-jetting heads (ink-jet recorder heads) for ejecting ink droplets and an ink-supplying device for feeding an ink to the heads.
The first form of said ink-jetting head is that generally called "single type" or "semi-multiple type", which has 1 to about 10 ink-discharging orifices. Since this form of ink-jetting head has a few ink-discharging orifices and consumes small amounts of ink, an ink-supplying device for this form of ink-jetting head can be relatively simply constructed by making use of an exchangeable ink tank of cartridge type and a single ink-supplying pipe.
On the other hand, another form of ink-jetting head, generally called "full-line multi-nozzle type", which prints letters or figures filling up one line of recording paper at nearly the same time, has a very large number of ink-discharging orifices and consumes ink incomparably larger amounts per unit time than the former simple form of ink-jetting head. Accordingly, an ink-supplying device for this full-line type of ink-jetting head is complicated in structure and large sized and requires special ink supply, thus needing considerably difficult techniques as compared with the former ink-supplying device.
At present, no practically useful ink-supplying device has yet been found that can supply ink to the full-line multiple type of ink-jetting head.